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most of the connecting straps are thin stainless steel alloy and i just use a sharp knife so that there is a tab to solder to .<br>in the case of a dud cell then leave the cell connector as long as possible.<br>been there done that many times and the tags seem to solder well with a larger soldering iron ie 30 watts plus<br><br><div>> Date: Tue, 18 Oct 2011 09:06:03 +1300<br>> To: chchrobotics@lists.linuxnut.co.nz<br>> From: markaren1@xtra.co.nz<br>> Subject: [chbot] Battery Pack - the 27 chocolate fish challenge<br>> <br>> Hi All,<br>> <br>> Last night Paul L was kind enough to give me a busted battery pack <br>> from an electric drill - www.idesignz.org/BP/battery_pack.jpg.<br>> <br>> The pack contains 10 x <br>> <http://www.idesignz.org/BP/DM_IMR18650E.pdf>http://www.idesignz.org/BP/DM_IMR18650E.pdf <br>> Lithium Ion cells.<br>> <br>> Two cells are busted, hence the reason for the unit being thrown out, <br>> and of course they are in the middle.<br>> <br>> The cells are capable of 20A discharge each, and two cells are in <br>> parallel. Short circuit current is likely in the order of 100A per <br>> cell given internal resistance of 35m ohms and 3.7V terminal voltage.<br>> <br>> The connecting tabs are copper sheet that have been sport welded onto <br>> the end of the cells.<br>> <br>> There is a black plastic saddle that the cells are attached (glued <br>> ?), with about 0.5mm clearance between cells. Max working temp is 65C.<br>> <br>> So the puzzle of the day is how to disassemble the pack safely.<br>> <br>> My inclination is to start by cutting vertically with an abrasive <br>> non-metallic dremel disk - at least the neighbours will be isolated then.<br>> <br>> Might then be tempted to soak in white spirit to dissolve the <br>> adhesive to the black saddle, but that may do nasty things to the <br>> green cell insulation.<br>> <br>> If you short adjacent cells you **will* start a very nasty fire.<br>> <br>> Any other thoughts ?<br>> <br>> -Mark<br>> <br>> <br>> _______________________________________________<br>> Chchrobotics mailing list Chchrobotics@lists.linuxnut.co.nz<br>> http://lists.ourshack.com/mailman/listinfo/chchrobotics<br>> Mail Archives: http://lists.ourshack.com/pipermail/chchrobotics/<br>> Web site: http://kiwibots.org<br>> Meetings 3rd Monday each month at Tait Radio Communications, 175 Roydvale Ave, 6.30pm<br>> <br>> When replying, please edit your Subject line to reflect new content.<br></div> </div></body>
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